[Bug c++/124229] [reflection] using type alias defined with splice expression of annotation as template arg T to extract causes ICE

[mpolacek at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124229

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot 
gnu.org

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Reduced:

```
#include <meta>

enum class E
{
  X [[=1]]
};

int main()
{
  template for (constexpr auto val : define_static_array (enumerators_of
(^^E)))
    {
      constexpr auto a = annotations_of(val)[0];
      using U = [:type_of(a):];
      constexpr auto m1 = extract<U>(a);
      constexpr auto m2 = extract<typename [:type_of(a):]>(a);
    }
}

```